pyrimidinones and Neutropenia

About 50% of patients with meta- static or inoperable melanoma carry a tumour with BRAF V600 mutation.The drug of first choice for these patients is vemurafenib, a BRAF inhibitor, which appears to prolong survival by a few months. Dabrafenib is a vemurafenib me-too with a slightly different known profile of adverse effects. Trametinib, a MEK inhibitor, is now authorised in the European Union for use in this setting, either as monotherapy or in combination with dabrafenib (marketed by the same company). Trametinib monotherapy has not been compared to BRAF inhibitor monotherapy. In a randomised, unblinded trial versus cytotoxic drugs in 322 patients, the median survival time did not differ statistically between the groups (15.6 versus 11.3 months; p = 0.09), but 65% of patients in the chemotherapy group received trametinib after disease pro- gression, making it more difficult to detect a difference between the groups. In an unblinded randomised controlled trial in 704 patients who had never received treatment for metastatic or inoperable disease, the trametinib + dabrafenib combination prolonged median survival by about 8 months more than vemurafenib. In another double-blind randomised controlled trial in 423 patients, median survival was about 6 months longer with trametinib + dabrafenib than with placebo + dabrafenib. The trametinib+ dabrafenibcombination was poorly effective after BRAF inhibitor failure in non-comparative trials including a few dozen patients in which the only endpoint was tumour response. Trametinib has many adverse effects, some of which can be life-threatening, such as heart failure, deep vein thrombosis, bleeding (including intracranial haemorrhage), neutropenia, and gastrointestinal perforation. Trametinib also causes retinal disorders and pneumonitis. Combining trametinib with dabrafenib reduces the risk of hyperkeratosis and skin cancer associated with dabrafenib, but increases the frequency of fever (including very high fever). Trametinib interactions mainly involve additive effects or antagonism. In practice, when a patient with metastatic or inoperable BRAF V600-positive melanoma is willing to accept the significant toxicity of trametinib in the hope of gaining several extra months of life, the trametinib + dabrafenib combination is a first-line option.

Topics: Heart Failure; Hemorrhage; Humans; Imidazoles; Intestinal Perforation; Intracranial Hemorrhages; MAP Kinase Kinase 1; Melanoma; Neutropenia; Oximes; Pneumonia; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Retinal Diseases; Skin Neoplasms; Survival Rate; Venous Thrombosis

This phase 1b study determined the safety, tolerability, and recommended phase 2 dose (RP2D) and schedule of trametinib in combination with gemcitabine. Secondary objectives included assessment of clinical activity and steady-state pharmacokinetics.. Adults with advanced solid tumours, adequate organ function and Eastern Co-operative Oncology Group performance status (ECOG PS) ⩽ 1 were eligible. Once-daily oral trametinib (1mg, 2mg, 2.5mg) was escalated in a 3+3 design with standard gemcitabine dosing (1000 mg/m(2) IV Days 1, 8, and 15 of 28-day cycles). During expansion, trametinib 2mg was combined with gemcitabine. Pharmacokinetics samples were collected on Day 15 pre-dose and 1, 2, 4 and 6h post-dose; tumour assessments were repeated every two cycles.. Between 8/2009 and 11/2010, 31 patients (pancreas = 11, breast = 6, non-small cell lung cancer (NSCLC) = 4, other = 10) were treated. Dose-limiting toxicities (DLTs) occurred in each cohort, and included febrile neutropenia, transaminase elevation and uveitis. The RP2D was declared as trametinib 2mg daily with standard gemcitabine dosing. Common grade 3/4 toxicities at the RP2D included: neutropenia (38%), thrombocytopenia (19%) and transaminase elevation (14%). Of 10 patients with measurable pancreatic cancer, three partial responses (30%) were documented; two additional patients achieved objective responses (breast, complete response (CR); salivary glands, partial response (PR)). Pharmacokinetics suggested no change in exposures of either drug in combination.. Administration of trametinib at its full monotherapy dose of 2mg daily in combination with standard gemcitabine dosing (1000 mg/m(2) IV Days 1, 8, and 15 every 28 days) was feasible. Though most toxicities were manageable, the addition of trametinib may increase gemcitabine-associated myelosuppression. Future studies of this combination will require monitoring to maintain dose and schedule.

Topics: Administration, Oral; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Deoxycytidine; Dose-Response Relationship, Drug; Female; Gemcitabine; Humans; Infusions, Intravenous; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Neutropenia; Pyridones; Pyrimidinones; Thrombocytopenia; Treatment Outcome

Inhibition of kinesin spindle protein or Eg5 causes the formation of monoastral mitotic spindles, which leads to cell death. AZD4877 is a specific, potent inhibitor of Eg5.. This was a Phase I, open-label, two-part study to evaluate the maximum tolerated dose (MTD) and safety and tolerability of AZD4877 in patients with advanced solid malignancies. In part A, the MTD of AZD4877, administered as three weekly 1-h intravenous (iv) infusions in a 28-day schedule, was determined by evaluating dose-limiting toxicity (DLT). In part B, the safety, tolerability, and pharmacokinetic profile of AZD4877 at the MTD were evaluated.. In part A, 29 patients received at least one dose of AZD4877 (5 mg, n = 4; 7.5 mg, n = 4; 10 mg, n = 3; 15 mg, n = 3; 20 mg, n = 3; 30 mg, n = 6; 36 mg, n = 3; 45 mg, n = 3). The MTD was defined as 30 mg, with the primary DLT being neutropenia. Although exposures appeared to be similar at the AZD4877 20 and 30 mg doses, dose reductions and omissions were higher in the 30-mg cohort; therefore, an intermediate dose, 25 mg, was evaluated in part B (n = 14). In part B, neutropenia remained the most commonly reported causally related adverse event. Exposure to AZD4877 was approximately dose proportional. Severity of neutropenia was related to exposure.. The MTD of AZD4877 given as a 1-h iv infusion on days 1, 8, and 15 of a 28-day cycle was 30 mg. At the selected 25 mg dose, AZD4877 had an acceptable safety profile.

Topics: Adult; Aged; Aged, 80 and over; Benzamides; Dose-Response Relationship, Drug; Female; Humans; Infusions, Intravenous; Kinesins; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Neutropenia; Pyrimidinones; Severity of Illness Index